The sport of golf has enjoyed tremendous popularity in recent times. Unfortunately, in many areas golf courses are overcrowded as new courses cannot be constructed fast enough to meet the surge in demand. As many recreational players will attest, golf can be a frustrating sport, especially when long waiting times and slow play hamper the player's ability to maintain even a consistent level of skill. Practice outdoor golf ranges are fairly common and serve to permit the player to practice a variety of shots with different clubs without the time commitment of playing 18 holes on a golf course. Indoor practice training devices are also available and these indoor facilities can remain open during times of the year when weather restricts play outdoors.
A number of golf practice aids have been developed including interactive video systems primarily for indoor use, such as the Birdie Rush manufactured by Joytec Ltd. of Burnaby, B.C., Canada. The available interactive video systems use several approaches for measuring the estimated speed and angle of the struck golf ball. Unfortunately, the estimated quantities do not predict with sufficient accuracy where a real golf ball would land and come to rest on a real golf course.
As is readily appreciated, wind speed, air temperature, air density, type of grass, type of ball, ball spin, and club affect the actual distance and path of a golf shot. Manufacturers of available interactive video games readily admit errors of 20%. However, skilled golfers, such as professionals and expert amateurs, can repeat a shot within 1%. Thus, an inaccurate system has little or no value to a skilled player as a golf practice aid. Interactive video systems do, however, offer entertainment for the player. For example, famous courses which are otherwise inaccessible may be readily programmed into a memory for display and simulated play. An example of a film-based simulation game is disclosed in U.S. Pat. No. 4,437,672 to Wilson. U.S. Pat. No. 3,712,624 to Conklin discloses a similar system including a screen for displaying a simulated position on a simulated golf hole layout wherein the trajectory of the struck ball is estimated based upon data from sensors positioned adjacent the tee area.
Outdoor golf practice ranges are available, and, such ranges include the effects of wind speed, air density, and other related factors on the flight of a struck golf ball which cannot be readily simulated. However, a golf practice range may be boring relative to the actual play, but is mandatory if improvement is desired.
A golf practice range cannot completely simulate actual shots on an 18 hole course. Attempts have been made to either increase the benefit gained by practicing at an outdoor range or to enhance its simulation of an actual golf course. For example, U.S. Pat. Nos. 4,192,510 and 4,283,056, both to Miller, disclose a computer-based video display of a simulated golf hole layout to be used in conjunction with an outdoor driving range. The display device is mounted adjacent the tee area of an outdoor practice range. After the player has executed a shot, the player then visually estimates the distance of the shot from a series of yardage markers on the target area. The player must then manipulate controls on the display device to "locate" the position of the shot on the simulated golf hole layout. Such a system, however, is more for entertainment than for serious practice as it is likely to be very inaccurate while at the same time being unnecessarily complicated for the player.
To increase the value of practice at a golf practice range, U.S. Pat. No. 4,673,183 to Trahan discloses a series of radar detecting units positioned at regular intervals and extending in a straight line outward from the tee area to thereby measure the distance of a shot and display the distance on a video display. The distance of the golf shot is estimated by determining the farthest away radar unit from the tee which detected the moving golf ball. However, the system provides only a gross estimate of the shot distance, and for a typical installation where the radar units have a detection range of 40 yards, the accuracy is only at best within 20 yards.
A substantial improvement in an automated system for measuring the distance of a golf shot at a practice range is disclosed in U.S. Pat. No. 5,029,866 to Beard, III et al. and assigned to the assignee of the present invention. An array of microphones or other acoustical detectors are positioned on the target area of the practice range. The signals generated by several adjacent sensors may be used to accurately determine the landing point of the struck golf ball by triangulation. The landing position of a golf ball is thus readily and accurately determined. Such information can be used to develop information of great benefit to the player. For example, the measured distances may be plotted in graphical form for a particular club, and statistical information, such as a mean distance for that club, may also be readily calculated. Although this system greatly improves the usefulness of golf practice, it measures only the impact location of a golf shot. But, the rolling of the golf ball after its initial impact, which may often be a significant component of the overall shot, is not determinable using the sensors alone.